With the development of wireless multimedia services, requirements on higher data rate and better user experience is growing, thereby requiring the traditional cellular network to have greater capability and coverage. On the other hand, in scenarios such as public security, social network, data sharing at short distance, local advertisement, requirements for Proximity Services (PS), through which a person may know and communicate with neighboring people or things, gradually increase. The traditional cellular network centers on a base station, and is significantly limited in support for high data rate and proximity services. In such a background, Device-to-Device (D2D) technology representing a new development direction of the technology of communications emerges. The application of the D2D technology may reduce the burden of the cellular network and power consumption of a user equipment, enhance data rate and improve the robustness of the network infrastructure, so as to satisfy the requirements of high data rate and proximity services described above.
The D2D technology may operate in an authorized or unauthorized frequency band, and allows a plurality of user equipments (UE) supporting D2D function (i.e., D2D UE) to discover/communicate directly with or without the network infrastructure.
FIG. 1 is a schematic diagram illustrating application scenarios of the D2D technology in the related art. As illustrated in FIG. 1, the D2D technology is mainly implemented in three types of patterns described below. In pattern 1, a data interaction is performed between UE 1 and UE 2 under the coverage of a cellular network, and the user plane data does not pass through the network infrastructure. In pattern 2, the UE in an area with poor coverage/without coverage relays the transmission. In this case, UE 4 with poor signal quality is allowed to communicate with a network via UE 3 covered by the network, thereby facilitating the Operator to expand coverage and increase capability. In pattern 3, UEs can communicate with each other directly when earthquake or emergency occurs and the cellular network malfunctions. In this case, both of the control plane data and user plane data among UE 5, UE 6 and UE 7 do not pass through the network infrastructure, and the data communication is single hopping or multi-hopping.
In addition, the D2D technology in the related art includes D2D discovery technology and D2D communication technology. The D2D discovery technology refers to the technology for judging/determining whether a first UE is adjacent to a second UE. A user equipment of the D2D can discover another user equipment of the D2D by transmitting or receiving a discovery signal/information. The D2D communication technology refers to the technology through which the user equipments of the D2D may communicate part or all of the communication data directly without using the network infrastructure.
Based on the characteristics and advantages of the D2D technology described above, it is proposed in the prior art to implement applications of Internet of Vehicle (IOV) using wireless cellular communication and D2D technology. The IOV supports the following scenarios for communication: instant messaging and vehicle warning. Vehicle warning may include collision warning, lane-change warning, etc. However, in this scenario, the requirements on delay are very strict, and the existing D2D technology cannot meet the requirements.
During the communication through the IOV, the communication between vehicles, which is also called as Vehicle to Vehicle (V2V) communication, needs to satisfy the requirements of low delay and high reliability in many scenarios. For example, if a distance between two vehicles is too short (that is, vehicle A is too close to vehicle B), it is required to pay attention to driving safety. FIG. 2 is a schematic diagram illustrating vehicular traffic in the related art. As shown in FIG. 2, vehicle B will fail to quickly prevent collision with vehicle A due to a relay in obtaining information about the location/speed of vehicle A if the information about the location/speed of vehicle A is reported to the network by vehicle A and then sent to vehicle B by a network-side equipment.
FIG. 3 is a schematic diagram illustrating communication through the IOV in the related art. As shown in FIG. 3, during the communication through the IOV, the communication between the vehicle and the network is called as Vehicle to Infrastructure (V2I) communication. The V2I communication is also called as V2R communication, where R refers to a Road Side Unit (RSU). The V2I communication and V2R communication refer to the communication between a vehicle and the network.
It is more appropriate to adopt the V2V communication in application scenarios related to vehicle safety. Further, the V2V communication may adopt the above D2D technology defined by the 3rd Generation Partnership Project (3GPP). Each vehicle supporting the V2V communication needs to obtain a resource necessary for communication (e.g., physical resources such as frequency and time slot of communication) to implement the V2V communication. In the case that the V2V communication adopts the D2D technology defined by the 3GPP, resources necessary for the V2V communication may be obtained through a contention mechanism. For example, a vehicle which obtains the resource first may use the resource first. However, through such mechanism, resource congestion and collision will occur if there are a plenty of vehicles in an area. For example, there is a resource block that has been allocated in advance, and a plurality of vehicles use a same resource including frequency resource and slot resource. As a result, none of these vehicles is able to use the resource, and information of these vehicles cannot be transmitted. Therefore, in the V2V communication, collision may easily occur if the vehicles obtain resources in the resource pool through a contention mechanism, resulting in that information of these vehicles cannot be sent out timely.
In other words, in the case that there are a plenty of vehicles in one area, the network may allocate and schedule resources for each of the vehicles to avoid the congestion caused by the resource contention among the vehicles. In this way, the vehicles will not simultaneously use the same resource in the V2V communication, so that information of each vehicle is sent out timely. That is to say, the V2V communication is required in the IOV application scenario related to vehicle safety, and delay or communication failure of the IOV, caused by resource collision during the V2V communication of the vehicles in the area with crowded vehicles, is required to be avoided.
In view of the above, the problem of the related art is that, when network side equipment allocates resources to a plenty of vehicles in an area crowded of vehicles, since the high-speed movement of the vehicles leads to handover between cells, the network fails to allocate and release resources for the vehicles timely.
At present, there is no effective solution proposed with respect to the problem described above.